对象没有属性questionNum

Question

我不确定我是否完全理解类/实例变量。我有这段代码：

class Question(object):

    """

    Exercise parameters

    """
    input_method = "MathKeyboard"
    difficulty = 4
    dirname = "../../../main/question_factory/int/generated_questions"


    """

    Initialize the exercise

    """

    def __init__(self, cur, new):
        questionFileName = self.dirname + "/" + self.question_file()
        self.questionNum = cur
        with open(os.path.abspath(os.path.join(os.path.abspath(os.path.dirname(__file__)), questionFileName)), 'rb') as questionFile:
            self.question = pickle.load(questionFile)

    def question_file(self):
        print self.questionNum <-
        return "difficulty" + str(self.difficulty) + "_" + str(self.questionNum) + ".question"

并发出错误'Question' object has no attribute 'questionNum' 在标记的线上。你能帮我解决这个问题吗？提前谢谢。

Answer 1

问题是，在初始化变量之前，请在question_file中调用__init__。首先设置变量。

class Question(object):

    """

    Exercise parameters

    """
    input_method = "MathKeyboard"
    difficulty = 4
    dirname = "../../../main/question_factory/int/generated_questions"


    """

    Initialize the exercise

    """

    def __init__(self, cur, new):
        self.questionNum = cur
        questionFileName = self.dirname + "/" + self.question_file()
        with open(os.path.abspath(os.path.join(os.path.abspath(os.path.dirname(__file__)), questionFileName)), 'rb') as questionFile:
            self.question = pickle.load(questionFile)

    def question_file(self):
        print self.questionNum
        return "difficulty" + str(self.difficulty) + "_" + str(self.questionNum) + ".question"